Construction in hazardous environments

1. Construction in hazardous environments 65 Bam, Iran, 2003 This session will look at both the security hazards and the natural hazards that effect the construction and planning of settlements

2. Sessionobjectives ! • The key learning objectives of this workshop are to form an • understanding of: • Workshop: group discussions on hazards affecting construction and planning • Presentation: security hazards including gender, protection and conflict • Presentation: natural hazards including flooding, earthquakes and landslides

3. Sessionobjectives ! • The key learning objectives of this workshop are to form an • understanding of: • Workshop: group discussions on hazards affecting construction and planning • Presentation: security hazards including gender, protection and conflict • Presentation: natural hazards including flooding, earthquakes and landslides

4. Discussion: 1 Each group has been allocated a type of hazard: Group 1: conflict Group 2: flooding Group 3: earthquake Group 4: storms Group 5: landslides Discussion in groups

5. Discussion: 2 Key point • In your groups,discuss and draw • the following measures that can help to • reduce peoples vulnerability : • any construction details or processes specific to the hazard • the key planning and site considerations for a planned settlement • the appropriate preparation orground works that should be carried out before construction begins 1. construction 2. planning 3. ground works Discussion in groups Each group agrees a key point

6. Sessionobjectives ! • The key learning objectives of this workshop are to form an • understanding of: • Workshop: group discussions on hazards affecting construction and planning • Presentation: security hazards including gender, protection and conflict • Presentation: natural hazards including flooding, earthquakes and landslides

7. Security: gender based issues • The following methods can reduce gender based discrimination: • design and construction • in most communities, women bear the primary responsibility undertaking household tasks should be reflected in design • latrines should not be located in poorly lit or remote areas • privacy and security is of primary importance, particularly during the night when risk of assault is high • in many communities women and girls expect to be provided with private spaces for activities such as changing clothes • site selection • sites should not be located near borders as this can increase the risk of abuse, abduction or forced recruitment • site planning shouldensure accessible services and resources to lower vulnerability of, for example, children travelling long distances to school, women collecting water and firewood • overcrowding can increase vulnerability, for example violence against women or young men being recruited into gangs or rebel groups Women, Girls, Boys and Men (IASC, 2006)

8. Protection: vulnerable groups • The following groups of people will need specific attention: • displaced unaccompanied children, are at particular risk from lack of appropriate shelter, for example, trafficking, violence, abuse and exploitation, therefore safe housing should be arranged and monitoring procedures initiated • unaccompanied older persons may also need targeted support if they are forced to construct their own shelters • ethnic or religious minorities may find themselves marginalised by the displaced and/or the host population • displaced families who do not own land or property may be even more vulnerable due to unclear legal support mechanisms Handbook for the Protection of Internally Displaced Persons (Global Protection Cluster Working Group, 2007)

9. Conflict: types ofbuilding damage • There are multiple hazards specifically associated with security • threats that may impact upon the built environment, for example: direct damage or threats to buildings from: • small arms, artillery fire, missiles, rockets and aerialbombardment • unexploded ordinance (UXOs) military activity for strategic military or political objectives, such as: • area denial weapons, such as land mines and booby traps • demolition charges • use of bulldozers to clear land • arson building vandalism caused by: • illegal building occupancy • civil unrest

10. Conflict: vulnerability of buildings • The extent, severity and vulnerability to damage dependson the • type of building as well as the hazard, for example the; • vulnerability of factories, apartment blocks, detached houses and commercial properties will depend on strategic importance, proximity to the front line and the topography of the surrounding area • method of construction will effect a buildings vulnerability to certain hazards, for example, this may depend on whether a structural frame or load bearing masonry is used • materials used and their associated properties, such as resistance to fire, tensile and compressive forces • location of the damage and its effect on the buildings structural stability, access and usability • Guidance from a structural engineer is required to determine if • damaged buildings should be repaired or demolished prior to • reconstruction.

11. Sessionobjectives ! • The key learning objectives of this workshop are to form an • understanding of: • Workshop: group discussions on hazards affecting construction and planning • Presentation: security hazards including gender, protection and conflict • Presentation: natural hazards including flooding, earthquakes and landslides

12. Natural hazards: an overview • 68 The main types of natural hazard that can pose serious risks to the built environment are: floods earthquakes tsunamis landslides volcanoes fires storms, and toxic environments

13. Natural hazards:floods • 69 • Floods can occur: • following sudden rainfall or snowmelt • when rivers break their banks • as a result of surges in sea level • as a result of rising ground water • Building design options include • raising the building on plinth • relocating the building locally to higher ground • raising the building on stilts • building strong columns and roof, but sacrificial walls that are washed out in floods • clear openings on opposite sides of the building parallel to the likely direction of water flood, such as under raised floors • strong corners and foundations to resist scouring, beams • barriers to divert flows and debris • Support traditional risk management techniques where possible • as this can help identify safer areas that are less likely to suffer • from flooding.

14. Natural hazards:earthquakes • 74 • Earthquake resistant settlement planning should ensure that: • settlements are not located on alluvial plains, unstable soils, reclaimed land, unstable or steep slopes • buildings are spaced to avoid multiple collapse • Earthquake resistant building design should be appropriate to: • geographic location • economic group • traditional construction • Design components may include: • a series of 3 ring beams per floor • ‘through stones’ joining front and rear faces of rubble masonry • columns able to take tension and compression • regular buttresses and dividing walls • continuous structural linkage between all building elements • fatigue stress is taken into account and effects monitored • square or rectilinear plans are used where possible

15. Natural hazards: tsunami • 83 • A tsunami is a large wave, or series of waves usually • caused by: • an earthquake • volcanic eruptions • underwater explosions or landslides • In tsunami prone areas site selection should ensure that • transitional settlements are located on high ground away from • the sea. • The impact of tsunami on settlements and populations can be • mitigated through: • relocation of communities at risk • identification of high ground for evacuation • identification of escape routes • reinforcement of flood defence systems including • through natural barriers such as reef, mangroves • and sandbanks • provision of Early Warning Systems

16. Natural hazards:landslides • 78 • The term ‘landslide’ includes rock slides, rock falls, tree slides, mud slides, debris flows, and avalanches • Past landslides should be assessed, including through consultation • with local communities • Landslides tend to occur on steep slopes or where land is • undercut by water • One indication of previous landslides is vegetation at a different level of growth from surrounding areas • Factors which can increase the risk of landslides: • deforestation • overgrazing • heavy rainfall • Foundation design can mitigate • against the effect of landslides • Where possible settlements should • not be located in areas prone to • Landslides. Properly draining a site • can also prevent landslides bend of river: risks of water undercutting land, causing landslide less danger of landslides damaging the settlement landslide risk to settlement

17. Natural hazards:volcanoes • 82 • Volcanoes produce various types of hazard: • hot ash and dust • mud and lava flows • fires • floods • landslides • rock slides • avalanches • poisonous gases • tsunami • ballistics (rocks thrown into the air) • Settlements should not be located near volcanoes or lava flows • Settlement planning should include escape routes and • contingency plans • Building design should ensure that • large openings face away from the volcano • roof design allows for ash loading

18. Natural hazards:storms • 72 • Storm damage can be lessened by influencing the flow of wind • through the site, for example: • using wind barriers, such as trees and topography may help to protect vulnerable shelters • the layout of buildings will effect how wind flows through the settlement • the positioning of windows and openings in buildings can be used to provide shelter as well as natural ventilation • Building design and retrofitting are measures that may include: • reducing overhangs, eves and gables • improving the strength of joints through the use of brackets and cross bracing • introducing cross bracing and ties especially for wall plates and rafters • improving the fixing of roofing materials • introducing storm shutters for windows and openings

19. Natural hazards:fire • 80 • The risk of fire is particularly high in dry areas where • forest fires or wildfires are common. • Also in cold or temperate climates where cooking and heating • stoves are used inside shelters. • Where possiblemethods for mitigating risks from fire include: • fire alarms and fire doors which should open in the direction of the escape • planning settlements to include fire breaks • providing water points and fire beaters for fire fighting • ensuring adequate fire escapes from buildings and fire drills • ensuring fire escapes are marked,clear and accessible the maximum travel distance to a fire escape should not be more than 18m from any part of the building distance between buildings should be twice their height

20. Natural hazards:toxic environments • Local knowledge is critical for understanding toxic threats • and sources of dangerous pollution • Toxic hazards may include: • contamination of surface or ground water • - arsenic • - chemical fertilisers or pesticides • - sewage • carbon monoxide and particulates emitted by vehicles, generators or stoves • asbestos, this should be removed and its use avoided in reconstruction • salt deposits from sea water flooding • human or animal bodies • abandoned lead mines • depleted uranium weapons

21. Bibliography ‘Handbook for the Protection of Internally Displaced Persons’ (Global Protection Cluster Working Group, 2007) ‘Women, girls, boys and men’(IASC 2006) ‘Transitional Settlement: Displaced Populations’ (Corsellis and Vitale, 2005) ‘Transitional settlement and reconstruction after natural disasters’(United Nations, 2008)